What are the other Names for this Condition? (Also known as/Synonyms)

• Cavitary (Invasive) Myiasis
• Myiasis of the Natural Body Cavities

What is Cavitary Myiasis? (Definition/Background Information)

• Myiasis is primarily a skin disease caused by several species of parasitic fly larva (of taxonomic order Diptera). The fly larvae (maggots) cause disease in humans and other vertebrate animals by feeding on the tissues. The infection is usually characterized by a painful, itchy, boil-like skin lesion that contains the parasite within it
• Cavitary Myiasis is a rare and severe form of myiasis that involves deeper tissues and organs present in the human body cavities. The human body cavities may be described as fluid-filled body recesses that encase and protect the internal organs. A few examples would include the cranial cavity, thoracic cavity, and abdominal cavity
• Based on the body cavity (anatomical structure) involved, Cavitary Myiasis is grouped into several subtypes that include:
  • Ocular myiasis
  • Oral cavity myiasis
  • Aural myiasis
  • Nasal myiasis
  • Tracheopulmonary myiasis
  • Cerebral myiasis
  • Intestinal myiasis
  • Urogenital myiasis
• The causative parasite may vary widely depending on the subtype of Cavitary Myiasis. Most cases are observed in a background of poor socioeconomic status, squalid conditions, and lack of hygiene, and are mainly reported from the poorer regions of the world
• Depending on the severity and body region/organs affected, Cavitary Myiasis can cause severe to extensive tissue destruction and present a host of serious complications such as hearing loss, respiratory distress, and brain infection
• Aggressive management of the myiasis (via invasive procedures), and antibiotic therapy for superimposed infections must be undertaken. The prognosis may vary widely from one individual to another, but can be generally good with prompt diagnosis and treatment

Who gets Cavitary Myiasis? (Age and Sex Distribution)

• Cavitary Myiasis may be observed in individuals of any age group; both children and adults are affected
• Both males and females are affected, and no gender preference is noted
• Worldwide, individuals of all racial and ethnic groups may be affected

A vast majority of cases are reported from the developing nations of Africa, Asia, and South America.

What are the Risk Factors for Cavitary Myiasis? (Predisposing Factors)

The following are the common risk factors for Cavitary Myiasis (mainly in the endemic regions). However, the specific risk factors depend on the part of the body affected such as the eye, brain, or abdomen.

• Living in poverty and overcrowded unclean surroundings
• Poor personal hygiene
• Traveling to the endemic regions
• Contact with infected animals in the endemic regions
• Lack of quality healthcare in the endemic regions
• Open suppurating wounds
• Elderly adults, especially those with certain neurodegenerative conditions
• Poor mental health
• Bedridden patients who cannot care for themselves
• Alcoholics and drug addicts

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Cavitary Myiasis? (Etiology)

The causative parasite of Cavitary Myiasis depends on the specific subtype of the condition, and on the geographical regions of the world. According to medical literature, most of the cases are attributed to Old World and New World screw-worms. 

What are the Signs and Symptoms of Cavitary Myiasis?

The signs and symptoms may vary from one individual to another and is based on the specific form of Cavitary Myiasis and the offending agent (larva species). However, the following may be noted in most individuals:

• Pain and discomfort in the affected region
• Partial to severe loss of function of the involved part
• Presence of a corresponding skin lesion at the site of involvement
• Bleeding or foul-smelling discharges
• Systemic signs and symptoms such as fever and chills

How is Cavitary Myiasis Diagnosed?

Cavitary Myiasis is diagnosed on the basis of the following information. The diagnostic techniques may vary based on the specific type of causative parasite, and on the body cavity involved.

• Complete physical examination and a thorough medical history evaluation, with emphasis on recent travel and/or handling of animals which may be infected
• Assessment of signs and symptoms
• Laboratory tests: Blood tests, such as complete blood count and peripheral blood smear
• Imaging studies, as necessary

A differential diagnosis to eliminate other similar conditions may be needed before arriving at a definitive diagnosis.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Cavitary Myiasis?

The complications of Cavitary Myiasis may generally include:

• Severe emotional stress
• Severe pain and discomfort
• Secondary infection of the abscess; rupture of the abscess
• Cellulitis: Skin infection that involves the deeper skin tissues
• Complete loss of function of the involved part such as hearing loss or blindness
• Hypereosinophilia and leukocytosis (increased white blood cells)
• Organ dysfunction and failure
• Severe inflammatory response to dead larvae or parts of larvae, especially during its removal
• Sepsis, which can be life-threatening

How is Cavitary Myiasis Treated?

The treatment for Cavitary Myiasis may involve the following measures:

• Manual removal or surgical extraction of larvae from affected region
• Surgical debridement of dead or necrotic tissue, if necessary
• Dressing and wound care, as required
• Administration of broad-spectrum antibiotics

Examination and identification of the larva following removal from skin tissues may be undertaken.

How can Cavitary Myiasis be Prevented?

Cavitary Myiasis may be prevented by considering the following measures:

• Maintaining basic personal and community hygiene and proper sanitation is highly important, particularly in the endemic zones
• Ensure that wounds and skin ulcers are properly treated and dressed/covered
• Washing hands after handling farm animals, especially horses and cattle
• Extra care should be taken while travelling to the endemic regions
• Try to cover all portions of the skin using long-sleeved shirts, full trousers, and socks to protect the body and skin from insect bites
• Use insect repellents to prevent the insects from entering residences
• Seek medical attention for any changes in skin; especially, after visiting known endemic regions
• The growth of adult flies must be effectively controlled and methods for eradication followed on a regular basis

What is the Prognosis of Cavitary Myiasis? (Outcomes/Resolutions)

The prognosis of Cavitary Myiasis is generally improved with treatment. However, the overall prognosis depends on the body part or organ affected and the promptness of treatment.

• Extensive tissue destruction and delayed/inadequate treatment may result in severe complications that may result in morbidities, or even be fatal
• In some individuals, rupture of an abscess containing the larva may lead to a severe inflammatory response
• Additionally, life-threatening sepsis may occur due to secondary infections

Additional and Relevant Useful Information for Cavitary Myiasis:

The following DoveMed website link is a useful resource for additional information:

https://www.dovemed.com/healthy-living/skin-disorders/